Z, ZX, and X-1: a realistic path to high fusion yield

Abstract

Z-pinches now constitute the most energetic and powerful sources of X-rays available by a large margin. The Z accelerator at Sandia National Laboratories has produced 1.8 MJ of X-ray energy, 280 TW of power, and hohlraum temperatures of 200 eV. These advances are being applied to inertial confinement fusion (ICF) experiments on Z. The requirements for high fusion yield are exemplified in the target to be driven by the X-1 accelerator. X-1 will drive two Z-pinches, each producing 7 MJ of X-ray energy and about 1000 TW of X-ray power. Together, these radiation sources will heat a hohlraum containing the 4-mm diameter ICF capsule to a temperature exceeding 225 eV for about 10 ns, with the pulse shape required to drive the capsule to high fusion yield; in the range of 200-1000 MJ. Since X-1 consists of two identical accelerators, it is possible to mitigate the technical risk of high yield by constructing one accelerator. This accelerator, ZX, will bridge the gap from Z to X-1 by driving an integrated target experiment with a very efficient energy source. ZX will also provide experimental confirmation that the full specifications of the X-1 accelerator for high yield are achievable, and that a realistic path to high fusion yield exists.